The present invention relates to an apparatus for raising animals, such as mice and rats, by supplying fresh air to a cage or cages.
Recently, there has been developed a method of supplying germ-free fresh air to a cage to rear relatively small experimental animals, such as mice and rats. For hermetical seal, the cage includes a substantially rectangular box-shaped casing with an open top, and a lid closing the open top of the casing. The cage is provided with openings formed through a rear side wall thereof for inserting air supply and exhaust conduits and a spout of a water dispenser, respectively. When the cage is placed in a received position in a cage rack, the air supply and exhaust conduits and a spout of a water dispenser which are provided to the cage rack sealingly pass through respective openings of the cage. An example of such a cage is disclosed in U.S. Pat. No. 4,346,672 to Niki.
When cages of this type are placed on a cage rack, experimental animals in the cages are liable to move lids, so that contaminated air can be exhausted from within the cages through the open tops thereof or the animals may escape from the cages. Various attempts have made to positively lock the lids of the cages but it is laborious to operate the lid locking mechanism for bringing animals into and out of the cages.